Overview
- The study was published Wednesday, September 16, 2026, in Science Advances and reports direct chemical temperature measurements from Tyrannosaurus rex teeth.
- Researchers measured how often specific carbon–oxygen isotope pairs bond in tooth enamel, using enamel’s strong resistance to chemical change as a durable record of the temperature when the enamel formed.
- The analyses returned a body‑temperature estimate near 36°C, a value the authors say is consistent with warm‑blooded physiology similar to large modern mammals.
- The team argues an internally regulated temperature would let T. rex sustain long activity, behave as an energetic predator or scavenger, and occupy high, cold latitudes across Late Cretaceous North America.
- The result is based on a small number of enamel samples—two from the museum specimen known as 'Thomas' plus an additional tooth in some comparisons—so broader sampling and independent replication are needed to confirm how widely the finding applies.